Counterclockwise magnetic fields in the Norma spiral arm

Abstract

Pulsars provide unique probes of the large-scale interstellar magnetic field in the Galactic disk. Up to now, the limited Galactic distribution of the known pulsar population has restricted these investigations to within a few kiloparsec of the Sun. The Parkes multibeam pulsar survey has discovered many more-distant pulsars which enables us for the first time to explore the magnetic field in most of the nearby half of the Galactic disk. Here we report the detection of counterclockwise magnetic fields in the Norma spiral arm using pulsar rotation measures. The fields are coherent in direction over a linear scale of $\sim 5$ kpc along the arm and have a strength of $-4.4\pm 0.9$ $\mu$G. The magnetic field between the Carina-Sagittarius and Crux-Scutum arms is confirmed to be coherent from $l\sim45\degr$ to $l\sim305\degr$ over a length of $\sim 10$ kpc. These results strengthen arguments for a bisymmetric spiral model for the field configuration in the Galactic disk.

minor changes

Cited by in corpus (25)

• Pulsar rotation measures and the large-scale structure of Galactic magnetic field
• Galactic Metallicity Gradients Derived from a Sample of OB Stars
• The FAST Galactic Plane Pulsar Snapshot survey: I. Project design and pulsar discoveries
• New pulsar rotation measures and the Galactic magnetic field
• The Galactic magnetic field and propagation of ultra-high energy cosmic rays
• The spatial energy spectrum of magnetic fields in our Galaxy
• Detecting Chameleons: The Astronomical Polarization Produced by Chameleon-like Scalar Fields
• Magnetic Fields in the Milky Way
• Arecibo 430 MHz Pulsar Polarimetry: Faraday Rotation Measures and Morphological Classifications
• The effect of HII regions on rotation measure of pulsars
• Milestones in the Observations of Cosmic Magnetic Fields
• Interstellar Hydroxyl Masers in the Galaxy. II. Zeeman Pairs and the Galactic Magnetic Field
• Dynamo activities driven by magneto-rotational instability and Parker instability in galactic gaseous disk
• Cosmic-ray positrons from millisecond pulsars
• Magnetic structure of our Galaxy: A review of observations
• Global Three-Dimensional MHD Simulations of Galactic Gaseous Disks: I. Amplification of Mean Magnetic Fields in Axisymmetric Gravitational Potential
• Polarization observations of nine southern millisecond pulsars
• New knowledge of the Galactic magnetic fields
• The High Time Resolution Universe Survey - IX: Polarimetry of long-period pulsars
• Peering into the Milky Way by FAST: III. Magnetic fields in the Galactic halo and farther spiral arms revealed by the Faraday effect of faint pulsars
• Measuring interstellar magnetic fields by radio synchrotron emission
• Magnetic fields of our Galaxy on large and small scales
• Magnetic fields in our Milky Way Galaxy and nearby galaxies
• A Method for Constraining Cosmic Magnetic Field Models Using Ultra-High Energy Cosmic Rays: The Field Scan Method
• Pulsars as excellent probes for the magnetic structure in our Milky Way